Abstract
The genus Myriococcum was described based on a sterile fungus producing sclerotia. Misinterpretation of these structures resulted in the later addition of several largely unrelated species to this genus and controversy about its phylogenetic placement.
The purpose of the study was to revise these species and elucidate their phylogenetic affinities. Based on available herbarium material and living strains, the type species of the genus, Myriococcum praecox, was placed in the family Stephanosporaceae (Agaricomycetes).
A new combination, Cryptendoxyla consimilis, is proposed for M. consimile belonging to the Sordariomycetes. A replacement name Crassicarpon hotsonii is proposed for M. thermophilum (Sordariomycetes).
Myriococcum spinuligerum most probably belongs to the Eurotiomycetes. The phylogenetic position of M. everhartii remains unclear.
The name M. sparsum must be treated as nomen dubium, because its description is based on a non-fungal organism.